A colorless to yellow odorless syrupy liquid&period; Corrosive to metals and tissue&period; Used to make cultured dairy products&comma; as a food preservative&comma; and to make chemicals&period;

Air & Water Reactions

Soluble in water&period;

Reactivity Profile

Lactic acid is a carboxylic acid&period; Carboxylic acids donate hydrogen ions if a base is present to accept them&period; They react in this way with all bases&comma; both organic &lpar;for example&comma; the amines&rpar; and inorganic&period; Their reactions with bases&comma; called "neutralizations"&comma; are accompanied by the evolution of substantial amounts of heat&period; Neutralization between an acid and a base produces water plus a salt&period; Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water&semi; those with more than six carbons are slightly soluble in water&period; Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions&period; The pH of solutions of carboxylic acids is therefore less than 7&period;0&period; Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt&period; Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt&period; Such reactions occur in principle for solid carboxylic acids as well&comma; but are slow if the solid acid remains dry&period; Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in Lactic acid to corrode or dissolve iron&comma; steel&comma; and aluminum parts and containers&period; Carboxylic acids&comma; like other acids&comma; react with cyanide salts to generate gaseous &period; The reaction is slower for dry&comma; solid carboxylic acids&period; Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous &period; Flammable and&sol;or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds&comma; dithiocarbamates&comma; isocyanates&comma; mercaptans&comma; nitrides&comma; and sulfides&period; Carboxylic acids&comma; especially in aqueous solution&comma; also react with sulfites&comma; nitrites&comma; thiosulfates &lpar;to give H2S and SO3&rpar;&comma; dithionites &lpar;SO2&rpar;&comma; to generate flammable and&sol;or toxic gases and heat&period; Their reaction with carbonates and bicarbonates generates a harmless gas &lpar;carbon dioxide&rpar; but still heat&period; Like other organic compounds&comma; carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents&period; These reactions generate heat&period; A wide variety of products is possible&period; Like other acids&comma; carboxylic acids may initiate polymerization reactions&semi; like other acids&comma; they often catalyze &lpar;increase the rate of&rpar; chemical reactions&period; Slowly corrodes most metals &lsqb;USCG&comma; 1999&rbrack;&period;

Health Hazard

Inhalation of mist causes coughing and irritation of mucous membranes&period; Ingestion&comma; even of diluted preparations&comma; has a corrosive effect on the esophagus and stomach&period; Contact with more concentrated solutions can cause severe burns of skin or eye&period;

Fire Hazard

Combustible material&colon; may burn but does not ignite readily&period; When heated&comma; vapors may form explosive mixtures with air&colon; indoors&comma; outdoors and sewers explosion hazards&period; Contact with metals may evolve flammable hydrogen gas&period; Containers may explode when heated&period; Runoff may pollute waterways&period; Substance may be transported in a molten form&period;